yeah it's fairly common...after years of use the tranny gears/dogs, shafts, forks all get worn, and all that extra free play, can cause it to bind....I just went through it this past year on my 500....my entire tranny had wear, so I just replaced the entire tranny. I doubt you'll have to go to that extreme, but don't be surprised if you have to replace more than just the fork. Definitely replace ALL the snap rings though!!
Make sure the dogs on 2nd and 3rd(and everything else) are within spec...or yes, you will be splittin the cases again much sooner than later.